Constructive Criticism wanted!

1. c4 is not a "poor opening". It is known as the English Opening (click on the link to learn more about it). As you can see from that article, 1... d5?! is the first "poor move" in this game, since after 2. cxd5 Qxd5 3. Nc3, you can keep developing your pieces and claiming the center while chasing around your opponent's queen.

3. e4? Have you heard of the en passant move? After 3... dxe3 (EP), you are forced to capture the black pawn with either 4. fxe3, which makes your king vulnerable, or 4. dxe3, which leads to 4... Qxd1 5. Kxd1, taking away your right to castle and moving your king towards that part of the board which you have already dangerously opened with your first two pawn moves.

7. Nfd2? I would have played Nbd2, since your other knight has nowhere else to go anyway, and your knight on f3 doesn't need to take a step backwards. Even Bd2 would have been better, prompting an exchange of knights and letting you develop.

Other than that, not bad. You capitalized well on your opponent's (numerous) mistakes!